Merge branch 'master' into v5-dev

conn_test.go

@@ -3,6 +3,7 @@ package pgx_test
 import (
 	"bytes"
 	"context"
+	"log"
 	"os"
 	"strings"
 	"sync"
@@ -784,6 +785,37 @@ func TestLogPassesContext(t *testing.T) {
 	}
 }
 
+func TestLoggerFunc(t *testing.T) {
+	t.Parallel()
+
+	const testMsg = "foo"
+
+	buf := bytes.Buffer{}
+	logger := log.New(&buf, "", 0)
+
+	createAdapterFn := func(logger *log.Logger) pgx.LoggerFunc {
+		return func(ctx context.Context, level pgx.LogLevel, msg string, data map[string]interface{}) {
+			logger.Printf("%s", testMsg)
+		}
+	}
+
+	config := mustParseConfig(t, os.Getenv("PGX_TEST_DATABASE"))
+	config.Logger = createAdapterFn(logger)
+
+	conn := mustConnect(t, config)
+	defer closeConn(t, conn)
+
+	buf.Reset() // Clear logs written when establishing connection
+
+	if _, err := conn.Exec(context.TODO(), ";"); err != nil {
+		t.Fatal(err)
+	}
+
+	if strings.TrimSpace(buf.String()) != testMsg {
+		t.Errorf("Expected logger function to return '%s', but it was '%s'", testMsg, buf.String())
+	}
+}
+
 func TestIdentifierSanitize(t *testing.T) {
 	t.Parallel()
 

copy_from.go

@@ -153,13 +153,13 @@ func (ct *copyFrom) run(ctx context.Context) (int64, error) {
 	<-doneChan
 
 	rowsAffected := commandTag.RowsAffected()
+	endTime := time.Now()
 	if err == nil {
 		if ct.conn.shouldLog(LogLevelInfo) {
-			endTime := time.Now()
 			ct.conn.log(ctx, LogLevelInfo, "CopyFrom", map[string]any{"tableName": ct.tableName, "columnNames": ct.columnNames, "time": endTime.Sub(startTime), "rowCount": rowsAffected})
 		}
 	} else if ct.conn.shouldLog(LogLevelError) {
-		ct.conn.log(ctx, LogLevelError, "CopyFrom", map[string]any{"err": err, "tableName": ct.tableName, "columnNames": ct.columnNames})
+		ct.conn.log(ctx, LogLevelError, "CopyFrom", map[string]any{"err": err, "tableName": ct.tableName, "columnNames": ct.columnNames, "time": endTime.Sub(startTime)})
 	}
 
 	return rowsAffected, err

logger.go

@@ -47,6 +47,14 @@ type Logger interface {
 	Log(ctx context.Context, level LogLevel, msg string, data map[string]any)
 }
 
+// LoggerFunc is a wrapper around a function to satisfy the pgx.Logger interface
+type LoggerFunc func(ctx context.Context, level LogLevel, msg string, data map[string]interface{})
+
+// Log delegates the logging request to the wrapped function
+func (f LoggerFunc) Log(ctx context.Context, level LogLevel, msg string, data map[string]interface{}) {
+	f(ctx, level, msg, data)
+}
+
 // LogLevelFromString converts log level string to constant
 //
 // Valid levels:

pgtype/pgtype_test.go

@@ -211,17 +211,17 @@ func (ci *pgCustomInt) Scan(src interface{}) error {
 }
 
 func TestScanPlanBinaryInt32ScanScanner(t *testing.T) {
-	ci := pgtype.NewMap()
+	m := pgtype.NewMap()
 	src := []byte{0, 42}
 	var v pgCustomInt
 
-	plan := ci.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, &v)
+	plan := m.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, &v)
 	err := plan.Scan(src, &v)
 	require.NoError(t, err)
 	require.EqualValues(t, 42, v)
 
 	ptr := new(pgCustomInt)
-	plan = ci.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, &ptr)
+	plan = m.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, &ptr)
 	err = plan.Scan(src, &ptr)
 	require.NoError(t, err)
 	require.EqualValues(t, 42, *ptr)
@@ -232,13 +232,13 @@ func TestScanPlanBinaryInt32ScanScanner(t *testing.T) {
 	assert.Nil(t, ptr)
 
 	ptr = nil
-	plan = ci.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, &ptr)
+	plan = m.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, &ptr)
 	err = plan.Scan(src, &ptr)
 	require.NoError(t, err)
 	require.EqualValues(t, 42, *ptr)
 
 	ptr = nil
-	plan = ci.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, &ptr)
+	plan = m.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, &ptr)
 	err = plan.Scan(nil, &ptr)
 	require.NoError(t, err)
 	assert.Nil(t, ptr)
@@ -246,10 +246,10 @@ func TestScanPlanBinaryInt32ScanScanner(t *testing.T) {
 
 // Test for https://github.com/jackc/pgtype/issues/164
 func TestScanPlanInterface(t *testing.T) {
-	ci := pgtype.NewMap()
+	m := pgtype.NewMap()
 	src := []byte{0, 42}
 	var v interface{}
-	plan := ci.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, v)
+	plan := m.PlanScan(pgtype.Int2OID, pgtype.BinaryFormatCode, v)
 	err := plan.Scan(src, v)
 	assert.Error(t, err)
 }

pgxpool/conn.go

@@ -2,7 +2,7 @@ package pgxpool
 
 import (
 	"context"
-	"time"
+	"sync/atomic"
 
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgconn"
@@ -26,9 +26,23 @@ func (c *Conn) Release() {
 	res := c.res
 	c.res = nil
 
-	now := time.Now()
-	if conn.IsClosed() || conn.PgConn().IsBusy() || conn.PgConn().TxStatus() != 'I' || (now.Sub(res.CreationTime()) > c.p.maxConnLifetime) {
+	if conn.IsClosed() || conn.PgConn().IsBusy() || conn.PgConn().TxStatus() != 'I' {
 		res.Destroy()
+		// Signal to the health check to run since we just destroyed a connections
+		// and we might be below minConns now
+		c.p.triggerHealthCheck()
+		return
+	}
+
+	// If the pool is consistently being used, we might never get to check the
+	// lifetime of a connection since we only check idle connections in checkConnsHealth
+	// so we also check the lifetime here and force a health check
+	if c.p.isExpired(res) {
+		atomic.AddInt64(&c.p.lifetimeDestroyCount, 1)
+		res.Destroy()
+		// Signal to the health check to run since we just destroyed a connections
+		// and we might be below minConns now
+		c.p.triggerHealthCheck()
 		return
 	}
 
@@ -42,6 +56,9 @@ func (c *Conn) Release() {
 			res.Release()
 		} else {
 			res.Destroy()
+			// Signal to the health check to run since we just destroyed a connections
+			// and we might be below minConns now
+			c.p.triggerHealthCheck()
 		}
 	}()
 }

pgxpool/pool.go

@@ -3,9 +3,11 @@ package pgxpool
 import (
 	"context"
 	"fmt"
+	"math/rand"
 	"runtime"
 	"strconv"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/jackc/pgx/v5"
@@ -77,10 +79,18 @@ type Pool struct {
 	beforeAcquire         func(context.Context, *pgx.Conn) bool
 	afterRelease          func(*pgx.Conn) bool
 	minConns              int32
+	maxConns              int32
 	maxConnLifetime       time.Duration
+	maxConnLifetimeJitter time.Duration
 	maxConnIdleTime       time.Duration
 	healthCheckPeriod     time.Duration
 
+	healthCheckChan chan struct{}
+
+	newConnsCount        int64
+	lifetimeDestroyCount int64
+	idleDestroyCount     int64
+
 	closeOnce sync.Once
 	closeChan chan struct{}
 }
@@ -109,14 +119,19 @@ type Config struct {
 	// MaxConnLifetime is the duration since creation after which a connection will be automatically closed.
 	MaxConnLifetime time.Duration
 
+	// MaxConnLifetimeJitter is the duration after MaxConnLifetime to randomly decide to close a connection.
+	// This helps prevent all connections from being closed at the exact same time, starving the pool.
+	MaxConnLifetimeJitter time.Duration
+
 	// MaxConnIdleTime is the duration after which an idle connection will be automatically closed by the health check.
 	MaxConnIdleTime time.Duration
 
 	// MaxConns is the maximum size of the pool. The default is the greater of 4 or runtime.NumCPU().
 	MaxConns int32
 
-	// MinConns is the minimum size of the pool. The health check will increase the number of connections to this
-	// amount if it had dropped below.
+	// MinConns is the minimum size of the pool. After connection closes, the pool might dip below MinConns. A low
+	// number of MinConns might mean the pool is empty after MaxConnLifetime until the health check has a chance
+	// to create new connections.
 	MinConns int32
 
 	// HealthCheckPeriod is the duration between checks of the health of idle connections.
@@ -163,9 +178,12 @@ func NewConfig(ctx context.Context, config *Config) (*Pool, error) {
 		beforeAcquire:         config.BeforeAcquire,
 		afterRelease:          config.AfterRelease,
 		minConns:              config.MinConns,
+		maxConns:              config.MaxConns,
 		maxConnLifetime:       config.MaxConnLifetime,
+		maxConnLifetimeJitter: config.MaxConnLifetimeJitter,
 		maxConnIdleTime:       config.MaxConnIdleTime,
 		healthCheckPeriod:     config.HealthCheckPeriod,
+		healthCheckChan:       make(chan struct{}, 1),
 		closeChan:             make(chan struct{}),
 	}
 
@@ -216,7 +234,7 @@ func NewConfig(ctx context.Context, config *Config) (*Pool, error) {
 	)
 
 	go func() {
-		p.checkMinConns() // reach min conns as soon as possible
+		p.createIdleResources(ctx, int(p.minConns))
 		p.backgroundHealthCheck()
 	}()
 
@@ -231,6 +249,7 @@ func NewConfig(ctx context.Context, config *Config) (*Pool, error) {
 // pool_max_conn_lifetime: duration string
 // pool_max_conn_idle_time: duration string
 // pool_health_check_period: duration string
+// pool_max_conn_lifetime_jitter: duration string
 //
 // See Config for definitions of these arguments.
 //
@@ -311,6 +330,15 @@ func ParseConfig(connString string) (*Config, error) {
 		config.HealthCheckPeriod = defaultHealthCheckPeriod
 	}
 
+	if s, ok := config.ConnConfig.Config.RuntimeParams["pool_max_conn_lifetime_jitter"]; ok {
+		delete(connConfig.Config.RuntimeParams, "pool_max_conn_lifetime_jitter")
+		d, err := time.ParseDuration(s)
+		if err != nil {
+			return nil, fmt.Errorf("invalid pool_max_conn_lifetime_jitter: %w", err)
+		}
+		config.MaxConnLifetimeJitter = d
+	}
+
 	return config, nil
 }
 
@@ -323,44 +351,105 @@ func (p *Pool) Close() {
 	})
 }
 
+func (p *Pool) isExpired(res *puddle.Resource[*connResource]) bool {
+	now := time.Now()
+	// Small optimization to avoid rand. If it's over lifetime AND jitter, immediately
+	// return true.
+	if now.Sub(res.CreationTime()) > p.maxConnLifetime+p.maxConnLifetimeJitter {
+		return true
+	}
+	if p.maxConnLifetimeJitter == 0 {
+		return false
+	}
+	jitterSecs := rand.Float64() * p.maxConnLifetimeJitter.Seconds()
+	return now.Sub(res.CreationTime()) > p.maxConnLifetime+(time.Duration(jitterSecs)*time.Second)
+}
+
+func (p *Pool) triggerHealthCheck() {
+	go func() {
+		// Destroy is asynchronous so we give it time to actually remove itself from
+		// the pool otherwise we might try to check the pool size too soon
+		time.Sleep(500 * time.Millisecond)
+		select {
+		case p.healthCheckChan <- struct{}{}:
+		default:
+		}
+	}()
+}
+
 func (p *Pool) backgroundHealthCheck() {
 	ticker := time.NewTicker(p.healthCheckPeriod)
-
+	defer ticker.Stop()
 	for {
 		select {
 		case <-p.closeChan:
-			ticker.Stop()
 			return
+		case <-p.healthCheckChan:
+			p.checkHealth()
 		case <-ticker.C:
-			p.checkIdleConnsHealth()
-			p.checkMinConns()
+			p.checkHealth()
 		}
 	}
 }
 
-func (p *Pool) checkIdleConnsHealth() {
+func (p *Pool) checkHealth() {
+	for {
+		// If checkMinConns failed we don't destroy any connections since we couldn't
+		// even get to minConns
+		if err := p.checkMinConns(); err != nil {
+			// Should we log this error somewhere?
+			break
+		}
+		if !p.checkConnsHealth() {
+			// Since we didn't destroy any connections we can stop looping
+			break
+		}
+		// Technically Destroy is asynchronous but 500ms should be enough for it to
+		// remove it from the underlying pool
+		select {
+		case <-p.closeChan:
+			return
+		case <-time.After(500 * time.Millisecond):
+		}
+	}
+}
+
+// checkConnsHealth will check all idle connections, destroy a connection if
+// it's idle or too old, and returns true if any were destroyed
+func (p *Pool) checkConnsHealth() bool {
+	var destroyed bool
+	totalConns := p.Stat().TotalConns()
 	resources := p.p.AcquireAllIdle()
-
-	now := time.Now()
 	for _, res := range resources {
-		if now.Sub(res.CreationTime()) > p.maxConnLifetime {
+		// We're okay going under minConns if the lifetime is up
+		if p.isExpired(res) && totalConns >= p.minConns {
+			atomic.AddInt64(&p.lifetimeDestroyCount, 1)
 			res.Destroy()
-		} else if res.IdleDuration() > p.maxConnIdleTime {
+			destroyed = true
+			// Since Destroy is async we manually decrement totalConns.
+			totalConns--
+		} else if res.IdleDuration() > p.maxConnIdleTime && totalConns > p.minConns {
+			atomic.AddInt64(&p.idleDestroyCount, 1)
 			res.Destroy()
+			destroyed = true
+			// Since Destroy is async we manually decrement totalConns.
+			totalConns--
 		} else {
 			res.ReleaseUnused()
 		}
 	}
+	return destroyed
 }
 
-func (p *Pool) checkMinConns() {
-	for i := p.minConns - p.Stat().TotalConns(); i > 0; i-- {
-		go func() {
-			ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
-			defer cancel()
-			p.p.CreateResource(ctx)
-		}()
+func (p *Pool) checkMinConns() error {
+	// TotalConns can include ones that are being destroyed but we should have
+	// sleep(500ms) around all of the destroys to help prevent that from throwing
+	// off this check
+	toCreate := p.minConns - p.Stat().TotalConns()
+	if toCreate > 0 {
+		return p.createIdleResources(context.Background(), int(toCreate))
 	}
+	return nil
 }
 
 func (p *Pool) createIdleResources(parentCtx context.Context, targetResources int) error {
@@ -371,6 +460,7 @@ func (p *Pool) createIdleResources(parentCtx context.Context, targetResources in
 
 	for i := 0; i < targetResources; i++ {
 		go func() {
+			atomic.AddInt64(&p.newConnsCount, 1)
 			err := p.p.CreateResource(ctx)
 			errs <- err
 		}()
@@ -449,7 +539,12 @@ func (p *Pool) Config() *Config { return p.config.Copy() }
 
 // Stat returns a pgxpool.Stat struct with a snapshot of Pool statistics.
 func (p *Pool) Stat() *Stat {
-	return &Stat{s: p.p.Stat()}
+	return &Stat{
+		s:                    p.p.Stat(),
+		newConnsCount:        atomic.LoadInt64(&p.newConnsCount),
+		lifetimeDestroyCount: atomic.LoadInt64(&p.lifetimeDestroyCount),
+		idleDestroyCount:     atomic.LoadInt64(&p.idleDestroyCount),
+	}
 }
 
 // Exec acquires a connection from the Pool and executes the given SQL.

pgxpool/pool_test.go

@@ -389,6 +389,14 @@ func TestConnReleaseClosesBusyConn(t *testing.T) {
 	c.Release()
 	waitForReleaseToComplete()
 
+	// wait for the connection to actually be destroyed
+	for i := 0; i < 1000; i++ {
+		if db.Stat().TotalConns() == 0 {
+			break
+		}
+		time.Sleep(time.Millisecond)
+	}
+
 	stats := db.Stat()
 	assert.EqualValues(t, 0, stats.TotalConns())
 }
@@ -413,6 +421,8 @@ func TestPoolBackgroundChecksMaxConnLifetime(t *testing.T) {
 
 	stats := db.Stat()
 	assert.EqualValues(t, 0, stats.TotalConns())
+	assert.EqualValues(t, 0, stats.MaxIdleDestroyCount())
+	assert.EqualValues(t, 1, stats.MaxLifetimeDestroyCount())
 }
 
 func TestPoolBackgroundChecksMaxConnIdleTime(t *testing.T) {
@@ -443,6 +453,8 @@ func TestPoolBackgroundChecksMaxConnIdleTime(t *testing.T) {
 
 	stats := db.Stat()
 	assert.EqualValues(t, 0, stats.TotalConns())
+	assert.EqualValues(t, 1, stats.MaxIdleDestroyCount())
+	assert.EqualValues(t, 0, stats.MaxLifetimeDestroyCount())
 }
 
 func TestPoolBackgroundChecksMinConns(t *testing.T) {
@@ -460,6 +472,21 @@ func TestPoolBackgroundChecksMinConns(t *testing.T) {
 
 	stats := db.Stat()
 	assert.EqualValues(t, 2, stats.TotalConns())
+	assert.EqualValues(t, 0, stats.MaxLifetimeDestroyCount())
+	assert.EqualValues(t, 2, stats.NewConnsCount())
+
+	c, err := db.Acquire(context.Background())
+	require.NoError(t, err)
+	err = c.Conn().Close(context.Background())
+	require.NoError(t, err)
+	c.Release()
+
+	time.Sleep(config.HealthCheckPeriod + 500*time.Millisecond)
+
+	stats = db.Stat()
+	assert.EqualValues(t, 2, stats.TotalConns())
+	assert.EqualValues(t, 0, stats.MaxIdleDestroyCount())
+	assert.EqualValues(t, 3, stats.NewConnsCount())
 }
 
 func TestPoolExec(t *testing.T) {
@@ -696,6 +723,14 @@ func TestConnReleaseDestroysClosedConn(t *testing.T) {
 	c.Release()
 	waitForReleaseToComplete()
 
+	// wait for the connection to actually be destroyed
+	for i := 0; i < 1000; i++ {
+		if pool.Stat().TotalConns() == 0 {
+			break
+		}
+		time.Sleep(time.Millisecond)
+	}
+
 	assert.EqualValues(t, 0, pool.Stat().TotalConns())
 }
 
@@ -784,7 +819,7 @@ func TestTxBeginFuncNestedTransactionCommit(t *testing.T) {
 				require.NoError(t, err)
 				return nil
 			})
-
+			require.NoError(t, err)
 			return nil
 		})
 		require.NoError(t, err)
@@ -834,6 +869,7 @@ func TestTxBeginFuncNestedTransactionRollback(t *testing.T) {
 
 		return nil
 	})
+	require.NoError(t, err)
 
 	var n int64
 	err = db.QueryRow(context.Background(), "select count(*) from pgxpooltx").Scan(&n)

pgxpool/stat.go

@@ -9,6 +9,9 @@ import (
 // Stat is a snapshot of Pool statistics.
 type Stat struct {
 	s                    *puddle.Stat
+	newConnsCount        int64
+	lifetimeDestroyCount int64
+	idleDestroyCount     int64
 }
 
 // AcquireCount returns the cumulative count of successful acquires from the pool.
@@ -62,3 +65,20 @@ func (s *Stat) MaxConns() int32 {
 func (s *Stat) TotalConns() int32 {
 	return s.s.TotalResources()
 }
+
+// NewConnsCount returns the cumulative count of new connections opened.
+func (s *Stat) NewConnsCount() int64 {
+	return s.newConnsCount
+}
+
+// MaxLifetimeDestroyCount returns the cumulative count of connections destroyed
+// because they exceeded MaxConnLifetime.
+func (s *Stat) MaxLifetimeDestroyCount() int64 {
+	return s.lifetimeDestroyCount
+}
+
+// MaxIdleDestroyCount returns the cumulative count of connections destroyed because
+// they exceeded MaxConnIdleTime.
+func (s *Stat) MaxIdleDestroyCount() int64 {
+	return s.idleDestroyCount
+}

rows.go

@@ -162,14 +162,15 @@ func (rows *baseRows) Close() {
 	}
 
 	if rows.logger != nil {
+		endTime := time.Now()
+
 		if rows.err == nil {
 			if rows.logger.shouldLog(LogLevelInfo) {
-				endTime := time.Now()
 				rows.logger.log(rows.ctx, LogLevelInfo, "Query", map[string]any{"sql": rows.sql, "args": logQueryArgs(rows.args), "time": endTime.Sub(rows.startTime), "rowCount": rows.rowCount})
 			}
 		} else {
 			if rows.logger.shouldLog(LogLevelError) {
-				rows.logger.log(rows.ctx, LogLevelError, "Query", map[string]any{"err": rows.err, "sql": rows.sql, "args": logQueryArgs(rows.args)})
+				rows.logger.log(rows.ctx, LogLevelError, "Query", map[string]any{"err": rows.err, "sql": rows.sql, "time": endTime.Sub(rows.startTime), "args": logQueryArgs(rows.args)})
 			}
 		}
 	}